Vaccination is one of the most important medical interventions for preventing disease. The purpose of vaccination is to induce an optimal immune response that provides preventive or therapeutic benefit to the host. Vaccines typically contain one or more immunogens (IMGs) that are harmless variants or derivatives of pathogens, which act to stimulate the immune system to mount defenses against the actual pathogen. There are many types of immunogens (IMGs), ranging from attenuated or killed microorganisms, microbial extracts, whole proteins, polysaccharides, and peptides. Some IMGs are very effective inducers of the desired immune response, while others require the co-administration of non-specific immune stimulants, or adjuvants, or the coupling of the IMG to a carrier protein or microparticulate substances. Still other IMGs are inherently poor at inducing effective immune responses, despite combination with adjuvants and repeated boosts. Many of these inherently weak immunogens are involved in diseases e.g., influenza and cancer, that remain major causes of human morbidity and mortality. There is a continuing need for effective and more potent vaccines, particularly those with the capacity to stimulate a robust immune response against weakly immunogenic targets.